US2297099A

US2297099A - Tunnel lining machine

Info

Publication number: US2297099A
Application number: US317962A
Authority: US
Inventors: John M Crom
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-02-08
Filing date: 1940-02-08
Publication date: 1942-09-29
Anticipated expiration: 1959-09-29

Description

sept. 29, 1942. M, ROM l 2,297,099

TUNNEL LINING MACHINE Filed Feb. 8, 1940 sheets-sheet 1 Sept. 29, 1942. J. M. cROM 2,297,099

TUNNEL LINING MACHINE Filed Feb. a, 1940 3 sheets-sheet 2 n Jolaj'ow 3M mw @M v A www Sept. 29, 1942. J. M. cRoM TUNNEL LINING MACHINE Filed Feb. 8, 1940 3 Sheets-Sheet 5 www Mlm-wf, y y

Patented Sept. 29, 1942 UNITED STATES PATENT OFFICE 14 Claims.

This invention relates to an apparatus for applying a coating of plastic material to the walls dening a passageway in accordance with the process described in my prior application Serial N0. 722,585 led April 26, 1934, now Patent No. 2,176,891, issued October 24, 1939. More specifically the present apparatus is an improvement over that described in my copending application Serial No. 301,077 filed October 24, 1939, of which this application is a continuation-impart. The improved machine of this invention is peculiarly adapted to the formation of mortar or cement coatings on the walls dening a passageway such as a ditch, a tunnel, a conduit, or the like and is eminently suited to the coating of such surfaces with plastic materials in general such, for example, as plaster, asphalt, waxes, resins, gum or the like.

Prior to the inventions described in the applications noted above, mortar coatings were applied by hand, that is, by the use of a pneumatic projecting device generally known as a Gunite or cement gun manually directed onto the surface to be covered. Even in coating small objects, hand operation of the projecting nozzle produces some unevenness of the coating and requires the application of a considerable excess of the coating material to assure thorough coverage. In coating large objects such as a ditch or a tunnel this unevenness and waste is greatly increased. Further, due to the uneven application, sand, which is intermixed with cement and water to form the mortar accumulates in small piles and a tendency to cause sand pockets and flaws in the coating is the result. These are particularly undesirable when water is to flow through the coated passage, as they retard the flow and allow water to seep out and undermine the structure.

These difficulties have been substantially overcome by means of the apparatus and processes described in my prior applications. It is now possible by means of those previous inventions to produce a lining that is smooth, even and free from flaws and sand pockets in an economical manner. Large savings in both labor and material are thereby achieved. The said prior inventions also provide for applying the coating in predetermined variable thicknesses at one or more longitudinal sections in order to avoid the usual effects of wear or strain. Thus the bottom of a ditch may be provided with a thicker lining than that applied to the sides of the ditch, whereby the greater effects of strain and Wear in this portion of the ditch are overcome.

In general, the apparatus of my invention comprises a machine that travels along the ditch, tunnel or the like and carries upon an arm extending from one end thereof the nozzle of a pneumatic mortar projecting device. Preferably, the machine carries a prime mover connected to means for driving the machine along the passage to be coated and to means for causing the nozzle carrying arm to rotate in the manner desired. Movement of the nozzle is such that the mortar or other plastic material is applied to the internal surface of the wall dening the passage in adjacent, partially overlapping strips each of which extends transversely of the ditch or, in the case of a completely enclosed passage such as a tunnel, the strips are arranged helically about the interior of the passage.

Although very good results have been obtained in actual use of the device disclosed in the prior applications noted above, it has now been found that the same may be substantially improved and superior linings formed by a certain combination of modifications described herein. In use of my earlier apparatus it has been found that as the nozzle carrying arm rotates or oscillates about r the axis thereof, mortar is deposited upon the surface to be coated and a substantial amount of sand rebounds and particles thereof are projected in all directions at random. This material tends to lodge at the bottom of the passage and may accumulate in piles on the uncoated portion of the passage prior to the portion upon which mortar is applied by the nozzle. When mortar is applied over such an accumulation of loose sand, a pocket of material having no ability to set firmly is incorporated in the lining. In order to avoid such weak places in the resultant structure, the present invention provides a brush moving about the passage in the same general direction as the nozzle and slightly in advance thereof to break up and spread sand accumulations in such a manner that the same may be incorporated in the lining as an integral part thereof. Preferably the mechanism is so formed with a pan and a guard apron adjacent the brush that the rebounding sand will accumulate in the bottom of the pan carried by the machine for periodic removal by the operator. The invention also contemplates arranging the Wheels with respect to the pan in such manner that the pan may be raised and lowered and that the possibility of sand going to the bottom of the passage to be coated through openings provided for the wheels will be substantially prevented.

It has also been found advantageous to use an air jet, either with the brush or alone, in order to remove and distribute sand deposits in advance of the jet.

Means are also provided to avoid weakening of the lining by particles of sand which rebound to the surface of mortar already applied. The means, preferably a trowel, used for this purpose are also effective in imparting a smooth surface to the finished lining. According to the invention the nozzle is followed by a screed to remove irregularities caused by projecting rivet heads or other inequalities in the surface to be coated. This element of the machine is in the nature of a cutting edge, similar to the edge of a trowel. The screed is preferably followed by the trowelling device noted above which imparts a smooth finish to the lining and incorporates therein any loose sand lying upon the exposed surface.

Ordinarily mortar deposited in accordance with my invention is relatively dry and the smoothing action of the trowel described above is rendered considerably more efficient if the surface of the lining is moistened slightly by a jet moving in advance of the trowel.

These and other objects and advantages of the invention will be apparent from the following detailed discussion of a preferred embodiment of the invention when considered in connection with the accompanying drawings wherein:

Figure 1 represents a horizontal section through a circular conduit with the present ma chine situated therein, showing the relationship of the parts of a machine with respect to a lining being deposited in said conduit;

Figure 2 is a vertical section through the conduit of Fig. 1, showing the machine in elevation;

Figure 3 is a section on line 3-3 of Fig. 2;

Figure 4 is a section on line 4-4 of Fig. 2;

Figure 5 is a detail view of the edge of the pan showing the manner in which the same is adapted to operation in a passage having a wire mesh reinforcing element arranged therein; and

Figure 6 is a cross-section on line 6-6 of Fig.. 5.

Referring specifically to Figures 1 and 2, which show the machine of this invention within a tubular conduit defined by a wall I0, upon which is deposited a lining II, the device comprises side frame members I2 and suitable cross beams I3 carrying the elements which apply and form the lining II. A pair of wheels I4 are mounted on the ends of an axle I5 connected to each end of the framework by means of brackets I6.

A prime mover of any suitable design such as the internal combustion engine indicated generally at I1 is mounted on cross beam members I3. It will be obvious that the prime mover may be an electric or compressed air rriotor ac cording to the circumstances under which it is to be used. Shaft IB driven by the motor I1 operates a train of gears in gear box I9 to drive shaft 20, upon which is mounted clutch 2I to furnish motive power for the wheels I4 as desired by the operator through chain 22 and sprocket 23, which sprocket is keyed to one of the axles I5. A pan 24 is carried below the framework of the machine to catch rebounding sand in the manner described above. The said pan is retained in its desired position by means of

brackets

21 and 28 connected to rod 29, which rod is in turn connected with frame members I2 by arms 30 and 3| through shafts 32. Rotation and adjustment of the shafts 32 is controlled by manual operation of the lever 33 keyed to one of said shafts. The two shafts are caused to move in unison by means of crank levers 34 keyed to said shafts and interconnected with the lever 33 by means of said shafts and the rods 35. It will be seen that when the lever 33 is moved through a suitable arc rotation of the shaft 32 will raise or lower the pan 24 through the medium of arms 30 and 3| operating upon the rod 29. An arcuate rack 36, or other suitable means for retaining the lever 33 in adjusted relation to the frame, is preferably provided.

Each of the wheels I4 is enclosed by a hood 36 formed integral with the pan 24, and each of the said hoods is provided with a slot 3l to permit raising and lowering of the pan 24 with respect to the rest of the machine.

That end of the pan 24 adjacent the nozzle and other apparatus for applying and forming the coating I I is provided with an apron member 38 fastened to said pan as by means of rivets 39 and having spring steel fingers 4I) extending beyond the edge of said pan. Figures 5 and 6 illustrate the function of the fingers 40 in providing an excellent seal against the passage of rebounding sand to the space beneath pan 24, when the machine is being used to line a passageway in which a mesh type reinforcing element has been placed to strengthen the plastic lining applied by the machine. It has been found advisable to raise the pan somewhat above the bottom of the passageway in moving the machine from one region to be coated to another region to be coated. Preferably the fingers are so formed that they will not contact the bottom of the passageway when the pan is so raised. It will be understood that the apron 38 is not an absolute essential to successful operation but it has been found that this type of structure contributes to the operation of the other elements to be hereinafter described to such an extent that the said apron is deemed to be highly advisable in the present structure.

Those elements of the device for preparing the surface of the passageway ID, applying the lining II thereto and finishing said lining are mounted upon a projecting end of a hollow shaft 4I having a conduit 42 for transporting mortar and a pipe 43 adapted to carry water disposed therein. Preferably, means are also provided for transporting compressed air through said shaft 43. The said shaft 4I is caused to rotate about its axis by power supplied thereto from drive shaft I8 through gears 44 and 45. Although my prior applications describe specifically a rna chine of the present type in which the mortar applying nozzle precedes the heavier portions of the machine in the direction of travel thereof, it will be noted that those applications also disclose the concept of so constructing the device that the mortar applying nozzle follows the wheel carried frame. According to the present invention, this latter expedient is deemed preferable and the machine is adapted to move in such direction that the lining is applied to portions of the passage already traversed by the wheel carried frame, Mounted on the shaft 4I to rotate therewith is a mortar applying nozzle 46 operating in substantially the manner disclosed in my prior applications. Mortar conveyed thereto through pipe 42 is projected together with water supplied through pipe 43 onto the inner surface of the wall IU to form the lining II.

EARHENVVAHF. APPARATUS.

As the nozzle 46 revolves, applying the lining II, sand rebounds from the surface treated in all directions. In order that piles of such sand may not accumulate under the lining applied, there is provided a brush 4l mounted on a spring arm 48 connected to the shaft 4I to rotate therewith. As the machine operates, the brush 4l disturbs and distributes sand deposits over the inner surface of the wall I Il in order that said sand may be incorporated in the lining I I as applied by the nozzle 46 immediately following said brush. A similar result may be obtained by the use of an air jet, such as 49, connected to a source of compressed air, not shown, either from a small air pump driven by the motor ll or from a remote supply of compressed air through the shaft 4I in the manner discussed above. In order to obtain best results I have found it is advisable to use both the brush 4l and the air jet 49 in combination, since the brush loosens and partially distributes sand which is thereafter entirely removed from the path of the nozzle by the air jet 49.

As noted above, rivet heads and other irregularities on the inner surface of the Wall Ill will tend to cause corresponding irregularities on the inner surface of the lining II. These projections, which tend to increase the resistance to the flow of uid within the finished passage are advantageously removed by means of a screed 50 having a sharp edge l carried by an arm 52 on the shaft 4I. Any such device that presupposes a true circular cross section of the passage is doomed to failure and it is therefore necessary that some provision be made for adapting the screed to follow irregularities in outline of the passage.

In the present embodiment of the invention this result is achieved by mounting the screed 50 on a shaft 53 mounted for relative sliding movement within a sleeve 54. There is provided a spring within the sleeve 54 which tends to urge the shaft 53 in a direction to cause the screed edge 5I to move toward the inner surface of the lining II with a force sufficient to accomplish the desired result.

As a final step in finishing the surface of the lining II a trowel 55 follows the screed about the inner surface of said lining. This trowel is also spring mounted, as on spring arms 56, in order that it shall be self-adjusting. Preferably a rod 5l is provided for the purpose of maintaining the trowel at a suitable angle with respect to the surface of the lining II. As a general rule, the mortar is applied by the nozzle 46 in a relatively dry condition and the surface thereof is usually subject to troweling only with considerable difficulty. The invention therefore preferably includes a water spray jet 58 supplied from the pipe 43 by a suitable connection, not shown. Both the water jet 58 and the spring arms 56 carrying the trowel 55 are mounted upon a suitable arm 59 connected to the shaft 4I for rotation therewith.

It will be seen that as the machine moves through the passage defined by the wall I0 (moving to the right in Figures 1 and 2) the sand rebounding from the mortar applied by nozzle 46 is projected either toward the unlined portion of the passage to be collected by pan 24 or distributed by brush 4'I and jet 49 or the sand is projected upon the lining already laid and is incorporated in that lining by the passage thereover of trowel 55. It also is apparent that both the brush 4l and the air jet 49 are practically 75 essential to successful collection and distribution of the rebounding sand when the machine is used in a passage lined with a mesh reinforcing element such as that shown in Figures 5 and 6. In such case the action of the brush and air jet cause a. portion of the sand to be carried over the apron 38 into the pan 24, while another portion is distributed to the left of the brush (Figures 1 and 2) to be incorporated in the finished lining.

The screed following the nozzle cuts off irregular projections in the yapplied lining and leaves the material so removed in a loose condition such that it is readily worked into the finished surface by the trowel 55. It will therefore be seen that each of the improving elements now formed as a part of the basic structure disclosed in my prior applications contributes to the single result of applying to the wall I0 a strong, smooth surfaced lining I I. Thus the action of the brush and air jet is of comparatively minor value unless there is provided means for collecting loose sand on that side of the brush remote from the nozzle and a means, such as trowel 55, on the other side of the brush .for working the rebound sand into the finished surface. But the action of the trowel will necessarily be rendered less efficient unless that element is preceded by some such device as the screed 50 to remove irregularities from the surface.

It will be understood that the present specific disclosure is presented as illustrative of a preferred embodiment and that numerous modifications may be made therein with the view to adapting the machine to any particular state of circumstances. By suitable modification of the means for driving the element carrying the nozzle and other movable parts, the device is readily adapted to the lining of passageways other than the circular conduits here described. A more detailed discussion of such modifications is given in my prior applications noted above, to which those skilled in the art are referred.

I claim:

1. In a machine for applying a coating to the inside side of a vpassage having a wheel carried horizontal frame and a mortar projecting nozzle mounted for rotary motion at one end thereof, a pan below said frame having an apron at the end thereof adjacent said nozzle comprising spring fingers extending over the edge of said pan and flared outwardly.

2. In a machine for applying a coating to the inside of a passage having a wheel carried horizontal frame and a mortar projecting nozzle mounted for rotary motion at one end thereof, means for distributing sand rebounding from mortar applied by said nozzle comprising a brush mounted for rotation intermediate said nozzle and said frame.

3. In a machine for applying a coating to the inside of a passage having a wheel carried horizontal frame and a mortar projecting nozzle mounted for rotary motion at one end thereof, means for distributing sand rebounding from mortar applied by said nozzle comprising an air jet mounted for rotation intermediate said nozzle and said frame.

4. In a device for lining a substantially circular passage of given radius; the combination of a substantially horizontal frame, a rotatable shaft extending longitudinally and projecting from one end of said frame and mounted for rotation thereon, wheels to carry said frame aligned with said shaft, the distance from the outside of said -wheels to the axis of said shaft being substantially equal to but not in excess of said given radius, adjustable mounting means connecting said frame and said wheels, means to rotate said shaft, means to rotate at least one of said wheels to drive said device, an arcuate pan mounted below said frame substantially parallel with the axis of said shaft and having recesses for said wheels, said pan being provided at the end thereof below the end of said frame from which said shaft projects with a plurality of spring fingers extending over the edge of said pan and being flared outwardly, a nozzle for applying a plastic material to the inner surface of said passage mounted on said shaft for rotation therewith in a plane at right angles to the axis thereof and spaced from said frame, means for supplying said plastic material to said nozzle, a brush mounted for rotation with said shaft in a plane at right angles to said axis intermediate said fingers and the said plane of said nozzle, an air jet mounted for rotation with said shaft in a plane parallel to and adjacent the said plane of said brush, means for supplying air under pressure to said jet, said brush and said air jet being spaced radially from the axis of said shaft a distance approximately equal to but not in excess of said given radius, a trowel mounted for rotation with said shaft in a plane Aparallel to the said plane of said nozzle and spaced therefrom on the side thereof remote from said frame, and a screed mounted for rotation with said shaft in a plane parallel to and intermediate the said planes of said nozzle and said trowel, said screed having its portion most remote from said shaft in the form of an edge parallel to said shaft, the radial distance of said screed and said trowel from said axis -being substantially equal to said given radius minus the thickness of the plastic lining applied by said nozzle.

5. In a device for lining a substantially circular passage of given radius; the combination of a substantially horizontal frame, a rotatable shaft extending longitudinally and projecting from one end of said frame and mounted for rotation thereon, wheels to carry said frame aligned with said shaft, the distance from the outside of said -wheels to the axis of said shaft being substantially equal to but not in excess of said given radius, mounting means connecting said frame and said wheels, means to rotate said shaft, means to rotate at least one of said wheels to drive said device, an arcuate pan mounted below said frame substantially parallel with the axis of said shaft, said pan being provided at the end thereof below the end of said frame from which said shaft projects with a plurality of spring fingers extending over the edge of said pan and being flared outwardly, a nozzle for applying a plastic material to the inner surface of said passage mounted on said shaft for rotation therewith in a plane at right angles to the axis thereof and spaced from said frame, means for supplying said plastic material to said nozzle, a brush mounted for rotation with said shaft in a plane at right angles t said axis intermediate said fingers and the said plane of said nozzle, and an air jet mounted for rotation with said shaft in a plane parallel to and intermediate the said planes of said brush and said nozzle, said brush and said air jet being spaced radially from the axis of said shaft a distance approximately equal to but not in excess of said given radius.

6. In a device for lining a substantially circular passage of given radius; the combination of a substantially horizontal frame, a rotatable shaft extending longitudinally and projecting from one end of said frame and mounted for rotation thereon, wheels to carry said frame aligned with said shaft, the distance from the outside of said wheels to the axis of said shaft being substantially equal to but not in excess of said given radius, mounting means connecting said frame and said wheels, means to rotate said shaft, means to rotate at least one of said wheels to drive said device, an arcuate -pan mounted below said frame substantially parallel with the axis of said shaft, said pan being provided at the end thereof below the end of said frame from which said shaft projects with a plurality of spring ngers extending over the edge of said pan and being flared outwardly, a nozzle for applying a plastic material to the inner surface of said passage mounted on said shaft for rotation therewith in a plane at right angles to the axis thereof and spaced from said frame, means for supplying said plastic material to said nozzle, a ybrush mounted for rotation with said shaft in a plane at right angles to said axis intermediate said fingers and the said plane of said nozzle said brush .being adjustably positioned so as to be adapted to brush the surface of the passage.

7. In a device for lining a substantially circular passage of given radius; the combination of a substantially horizontal frame, a rotatable shaft extending longitudinally and projecting from one end of said frame and mounted for rotation thereon, wheels to carry said frame aligned with said shaft, the distance from the outside of said wheels to the axis of said shaft being substantially equal to but not in excess of said given radius, mounting means Iconnecting said frame and said wheels, means to rotate said shaft, :means to rotate at least one of said wheels to drive said device, an arcuate pan mounted below said frame substantially parallel with the `axis of said shaft, said pan being provided at the end thereof below the end of said frame from which said shaft projects with a plurality of spring lingers extending over the edge of said pan and being flared outwardly, a nozzle for applying a plastic material to the inner surface of said passage mounted on said shaft for rotation therewith in a plane at right angles to the axis thereof and spaced from said frame, means for supplying said plastic material to said nozzle, and an air jet mounted for rotation with said shaft in a plane at right angles to said axis intermediate said ngers and the said plane of said nozzle.

8. In a device yfor lining a substantially circular passage of given radius; the combination of a substantially horizontal frame, a rotatable shaft extending longitudinally and projecting from one end of said frame and mounted for rotation thereon, wheels to carry said frame aligned with said shaft, the distance from the outside of said wheels to the axis of said shaft being substantially equal to but not in excess of said given radius, mounting means connecting said frame and said wheels, means to rotate said shaft, means to rotate at least one of said wheels to drive said device, a nozzle for applying a plastic material to the inner surface of said passage mounted on said shaft for rotation therewith in a plane at right angles to the axis thereof and spaced from said frame, means for supplying said plastic material to said nozzle and a screed mounted for rotation with said shaft in a plane parallel to the said plane of said nozzle and spaced therefrom on the side thereof remote from said frame, said screed having its portion most remote from said shaft in the form of an edge parallel to said shaft and .be-

ing resiliently mounted for movement of said edge toward and away from said axis.

9. In a device for lining a substantially circular passage of given radius; the combination of a substantially horizontal frame, a rotatable shaft extending longitudinally and projecting from one end of said frame and mounted for rotation thereon, wheels to carry said frame aligned with said shaft, the distance from the outside of said wheels to the axis of said shaft being substantially equal to but not in excess of said given radius, mounting means connecting said frame and said wheels, means to rotate said shaft, means to rotate at least one of said wheels to drive said device, a nozzle for applying a plastic material to the inner surface of said passage mounted on said shaft for rotation therewith in a plane at right angles to the axis thereof and spaced from said frame, means for supplying said plastic material to said nozzle, a trowel mounted for rotation with said shaft in a plane parallel to the said plane of said nozzle and spaced therefrom on the side thereof remote from said frame and means for spraying water to said inner surface of said passage mounted for rotation with said shaft in a plane parallel to and intermediate the said planes of said nozzle and said trowel.

10. In a device for lining a substantially circular passage of given radius; the combination of a substantialy horizontal frame, a rotatable shaft extending longitudinally and projecting from one end of said frame and mounted for rotation thereon, wheels to carry said frame aligned with said shaft, the distance from the outside of said wheels to the axis of said shaft being substantially equal to but not in excess of said given radius, mounting means connecting said frame and said wheels, means to rotate said shaft, means to rotate at least one of said wheels to drive said device, a nozzle for applying a plastic material to the inner surface of said passage mounted on said shaft for rotation therewith in a plane at right angles to the axis thereof and spaced from said frame, means for supplying said plastic material to said nozzle, a trowel mounted for rotation with said shaft in a plane iparallel to said plane of said nozzle and spaced therefrom on the side thereof remote from said frame, and a screed mounted for rotation with said shaft in a plane parallel to and intermediate said planes of said nozzle and said trowel, said screed having its portion most remote from said shaft in the form of an edge parallel to said shaft, the radial distance of said screed and said trowel from said axis being substantially equal to said given radius minus the thickness of the plastic lining applied by said nozzle.

11. In a device for lining a substantially circular Ipassage of given radius; the combination of a substantially horizontal frame, a. rotatable shaft extending longitudinally and projecting from one une bil HUUHI end of said frame and mounted for rotation thereon, wheels to carry said frame aligned with said shaft, the distance from the outside of said wheels to the axis of said shaft being substantially equal to -but not in excess of said given radius, mounting means connecting said frame and said wheels, means to rotate said shaft, means to rotate at least one of said wheels to drive said device, a trowel mounted for rotation with said shaft in a plane parallel to the said plane of said nozzle and spaced therefrom on the side thereof remote from said frame, a screed mounted for rotation with said shaft in a plane parallel to and intermediate the said planes of said nozzle and said trowel, said screed having its portion most remote from said shaft in the form of an edge parallel to said shaft, the radial distance of said screed and said trowel from said axis being substantially equal to said given radius minus the thickness of the plastic lining applied by said nozzle, and means for spraying water to the surface of said lining mounted for rotation with said shaft in a plane parallel to and intermediate the said planes of said trowel and said screed.

12. In a machine for applying a coating to the inside of a passage having a wheel carried horizontal frame and a mortar projecting nozzle mounted for rotary motion at one end thereof, means for distributing sand rebounding from mortar applied by said nozzle comprising a brush mounted for rotation intermediate said nozzle and said frame, and a pan having a marginal portion located near the path of movement of said brush, for receiving surplus sand and the like distributed thereby said brush and pan being located adjacent the surface of the passage to be lined.

13. In a machine for applying a coating to the inside of a passage having a wheel carried horizontal frame and a mortar projecting nozzle mounted for rotary motion at one end thereof, means for distributing sand rebounding from mortar applied by said nozzle comprising an air jet mounted for rotation intermediate said nozzle and said frame, and a pan having a marginal portion located near the path of movement of said jet, for receiving surplus sand and the like distributed thereby said jet and said pan being located adjacent the surface of the passage to be lined.

14. In a machine for applying a coating to the inside of a passage having a horizontal frame Imounted upon 'wheels and a mortar projecting nozzle mounted for rotary motion at one end thereof, a screed mounted for rotation on the side of said nozzle remote from said frame, comprising an edge parallel to the axis of rotation thereof, said edge being adapted to be spaced inwardly from the bottom of the wheels a distance equal to the thickness of the lining being applied.

JOHN M. CROM.